THEORY OF OPERATION
contains the overall functional description of the radio set
for transmit and receive operation, followed by a brief
description of each module. It supports the operator's
and organizational level of maintenance for unit
This chapter contains the functional theory of
Section II contains a functional block
operation of the radio set. The information is provided
description of each of the seven radio set modules to
to enable the operators and organizational maintenance
provide a more detailed level of understanding of the
personnel to understand the overall function and
radio set operation.
capabilities of the radio set.
OVERALL FUNCTIONAL DESCRIPTION
audio signals are routed through the control panel to the
modulator/demodulator. The Xmt Audio mixes with the
three LO signals sent from the synthesizer to produce a
This section describes the overall function of the
single sideband Xmt RF output. The low power Xmt RF
radio set, and discusses the transmit and receive
is amplified in the power amplifier and routed through the
operation at the module level. It also briefly discusses
harmonic filter to remove transmitter harmonics. The
the function of each module.
filtered Xmt RF is then applied to the antenna, via the
RADIO SET FUNCTIONAL DESCRIPTION.
The Rcv RF signal
The radio set is a 2- thru 30-MHz single
from the antenna is routed back through the antenna
sideband (SSB) transceiver with a transmitter output of
tuner and is filtered by the harmonic filters to remove
20 watts. Operation can be either voice, cw, or coded
The Rcv RF is then routed to the
data (depending on the audio device used) with
modulator/demodulator where it mixes with the three LO
automatic antenna tuning.
There are three levels of
signals sent from the synthesizer to produce the Rcv
frequency conversion between audio and rf in both
Audio output. The Rcv Audio is then routed through the
transmit and receive with two stages of intermediate
control panel to the handset.
frequency (if.) amplification and filtering. The radio set
consists of seven functional modules.
Five of the
3-10. CONTROL PANEL (Figure 3-2).
modules are housed in the receiver/exciter unit:
receiver/exciter control panel provides operational control
of the radio set. It couples voice or CW key from the
audio devices in use by the operator, and has controls
for selection of frequency, volume, mode, and sideband
Select and Sideband Select signals are routed to the
synthesizer, and the Frequency Select signal also to the
antenna tuner. Filter Select signals are routed to the
Two functional modules are housed in the
harmonic filter. Volume control, mode select and Xmt
Audio are applied to, and Rcv Audio is received from, the
modulator/d -modulator. The control panel also
1. Power amplifier
2. Antenna tuner
TRANSMIT OPERATION (Figure 3-1).